People visit a calligraphy exhibition by Pang Zhonghua, a well-known pioneer of hard nib calligraphy in China, during an event to celebrate the UN Chinese Language Day at UN headquarters in New York, on April 20, 2017. The UN Chinese Language Day has been observed annually on April 20 since 2010 to celebrate the language's overall contribution to the world and encourage more people to take it up. (Xinhua/Li Muzi)
